A new satellite-based technology from Google, Oceana, and SkyTruth aims to help governments and the public track the movement of tens of thousands of fishing vessels across the world, in nearly real time. (Courtesy of Oceana)

Illegal and unreported fishing is a multibillion-dollar business around the globe, and one that has proven notoriously difficult to combat. In part, that’s because it involves a constant stream of renegade fishermen being pursued by countries that have only limited resources to carry out a perpetual cat-and-mouse game on the high seas.

But a new satellite-based surveillance system powered by Google, which will be publicly unveiled Thursday at a global oceans conference at the State Department, aims to help alter that equation. Global Fishing Watch, as it is called, is designed to act as an eye in the sky, constantly scouring the globe in search of those illegally plundering the oceans. The organizations that partnered to develop it, which include the marine-advocacy group Oceana and West Virginia-based nonprofit SkyTruth, say the free platform will help governments, journalists and everyday citizens monitor roughly 35,000 commercial fishing vessels nearly in real time.

“We will be able to see a lot of information about who is fishing where,” said Jacqueline Savitz, vice president for U.S. oceans at Oceana, adding that the platform will help “revolutionize the way the world views commercial fishing.”

The technology uses public broadcast data from the Automatic Identification System (AIS), which uses satellite and land-based receivers to track the movement of ships over time. Not all fishing vessels willingly broadcast their location, of course — particularly those intent on breaking the law — and vessels can switch off their trackers, potentially hindering the usefulness of the new technology. The United States and other countries already require vessels of a certain size to use the locator system, partly as a safety measure to avoid collisions at sea, and more countries are beginning to follow suit. Global Fishing Watch allows users to access that information to track specific vessels over time, going back to 2012.

Savitz said she believes the tool will have an array of uses. Governments could use it to monitor and enforce fishing restrictions in their waters. Journalists and the public can use it to search for suspicious fishing activity, such as vessel that suddenly seems to disappear or one that rarely comes to port, and to make sure officials are safeguarding marine protected areas. Insurance companies can track the vessels they insure.

“We’re hoping it will be useful to a lot of different sectors,” Savitz said.

The use of satellites to patrol environmental activities both on land and at sea has grown steadily in recent years. Early last year, the Pew Charitable Trusts launched a similar technology aimed at helping authorities detect and respond to pirate fishing in the oceans. Known as Project Eyes on the Seas, it was developed alongside a British company and uses various satellite tracking data to help track suspicious vessel movements of fishing ships at sea.

“You can track anything in the world from anywhere in the world,” SkyTruth’s president, John Amos, whose work has helped reshape environmental watchdog efforts, told The Washington Post for a magazine story in 2013.

Global Fishing Watch, which has been under development for two years, has shown flickers of success. The government of the Pacific island nation of Kiribati used it to document how a tuna-fishing vessel had operated illegally inside the Phoenix Islands Protected Area, which had been declared off-limits to commercial fishing in early 2015. The episode resulted in a $1 million fine — a large sum for such a tiny government.

Using satellite-based technology, Global Fishing Watch is a new system keeping tabs on fishing vessels to prevent illegal and unreported fishing. (Oceana)

The new technology being unveiled Thursday is one piece of a much broader international push to reduce overfishing in the oceans and cut back in particular on illegal fishing, which can deplete fish populations, harm local habitats and have serious economic consequences.

“The problem is just gigantic,” Secretary of State John F. Kerry said in an interview this week with The Post. “A third of the world’s fisheries are overfished, and the ones that aren’t overfished are at max, with more and more demand. Half the world’s population, basically, relies on protein from the ocean to survive. It’s an ecosystem that requires sustainability to survive, and we’re not treating it in a sustainable fashion.”

Earlier this year, a first-of-its-kind international treaty designed to help stop illegal fishing entered into force after being ratified by dozens of countries. The accord, known as the Port State Measures Agreement, is aimed at improving the ability to detect illegal fishing, stop illegally caught fish from reaching ports and markets and sharing information about illicit fishing vessels among nations.

Under the agreement, a country can deny ships suspected of illegal fishing entry into port or refuse to let them offload fish or refuel. Fishing vessels that want to enter a given port also must request permission ahead of time, detail what fish they have on board and verify that it was caught legally.

In addition, U.S. and international officials have been coordinating on ways to better share information in an effort to detect and halt illegal fishing around the globe, and to prosecute those involved. Officials plan to release more specifics about those efforts at this week’s “Our Ocean” conference.

At the same time, individual countries are taking their own actions. Indonesia, for example, recently sank 60 boats that it had impounded for illegally fishing in its waters, part of an aggressive campaign to deter the practice and assert sovereignty over one of its key resources.

Kerry said both new technologies and more aggressive efforts to fight the problem are essential, because demand for fish will continue to increase as populations grow and massive numbers of people in countries such as China and India escape poverty. For the oceans to continue to provide food and livelihoods for billions of people each day, he said, the world has to treat them like the fragile resource they are.

“We have to find a way to enforce [fishing laws]. We have to find a way to monitor it. And that’s very difficult in vast oceans with resources that are [limited],” Kerry said, adding, “We’re trying to create accountability where there is very little. You can’t have impunity on this and expect to win this battle.”